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[Question] Can you generate electric while driving to a depleted battery?

Discussion in 'Prime Technical Discussion' started by PixelRogue, Nov 13, 2016.

  1. PixelRogue

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    To explain:

    • Prius V Gen3 cars will travel around a while in "golf cart mode." Once depleted, you can generate enough energy to return to golf cart mode.
    • Prius PIP cars will travel about 10-12 miles on electric, but once the battery is depleated it is nearly impossible to get back into electric mode without plugging the car into an outlet.
    Having both a 2010V and 2012PIP, got to say I truly miss the ability to regenerate the battery of the 2010 when driving the PIP. How does this work on the Prime?
     
  2. bisco

    bisco cookie crumbler

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    i think your mixing metaphor's.:cool: you can regenerate the same amount of electricity in a pip as you can in the hybrid prius, and drive around in 'golf cart mode' with a light foot, but without the ev button. but the only way to regenerate enough to get into ev is down a big hill.
    prime will be the same except you now have the ability to recharge the battery with the engine.
     
  3. drysider

    drysider Active Member

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    Not owning a PIP, I do not realize they could not charge from the engine.
     
  4. Lee Jay

    Lee Jay Senior Member

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    Up to 80% of full Ev range (i.e. 20 miles nominally).
     
  5. bisco

    bisco cookie crumbler

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    i think there have been a lot of complaints about this, leading to the new feature.
     
  6. fotomoto

    fotomoto Senior Member

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    Pixel,

    In my Energi, I've found a way to get more EV miles while using the gas engine when driving at higher speeds. I call it EV banking. See if you can duplicate this method in the PIP.

    1) Just before you run out of EV miles, say, 1-2 miles left,
    2) Switch from EV mode to Hybrid (gas) mode and continue driving
    3) before slowing down return to EV mode and then perform your regen braking
    4) Before accelerating again, switch back to hybrid mode.
    5) rinse, lather, repeat.

    This doesn't work if you're driving non-stop (interstate).

    This allows the set point of the SOC (state of charge) to move up adding EV miles to the battery from all the regen. Once I'm back to city speeds, I move back to EV mode a final time and use up the battery as I come back home. Since I know mileage distances close to my house, it's a fun game to see how close I can get to zero as I pull into my neighborhood.
     
  7. john1701a

    john1701a Prius Guru

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    Stacking had always been possible for PIP. You just have to know how & when. Prime makes it much easier though.
     
  8. Pizza Driver

    Pizza Driver Active Member

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    How? The method described by fotomoto seems like a pain.
     
  9. Ashlem

    Ashlem Senior Member

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    Keep in mind that you'll never regain 100% of your energy usage back via regen braking due to physics. You're going to lose some of the energy from friction, such as while the car is driving through air, and some of it is sapped from the road via the tires.

    In my Chevy Volt, the gas engine will never fully recharge the battery, though this was by design. At most it'll run to keep the battery at around 40% to keep a buffer so if I'm going up a long mountain pass, the electric motor and the gas engine can work together to go up at a fast speed. The gas engine by itself isn't powerful enough to haul the 3700 pounds up at higher speeds most people usually drive.

    To fully charge, I have to plug it in. Or go down a very long hill.

    The non-plug in Priuses also have a very small battery size, around 1 kWh or so, compared to 8.8 kWh in the Prime, or 16.5 kWh in my Volt, so it doesn't take very long to recharge it. But running a gas engine to charge it is the least efficient way to do it, since the engine has generate electricity to send to the battery, which then sends it to the electric motor to spin the wheels, with slight energy conversion losses at each step.

    If you don't mind "cheating", you can probably also recharge via a tow truck with all 4 wheels on the road. Some guys in Russia did this in a Tesla Model S.

    Watch This Tesla Model S Get Charged By Being Towed - Video
     
  10. Tideland Prius

    Tideland Prius Moderator of the North
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    I think he means just using the CHG function and the gas engine to charge the battery up, rather than the stacking method.
     
  11. bisco

    bisco cookie crumbler

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    and don't use b mode unless you're coming down a uge vermont mountain.
     
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  12. Optimus PRIME

    Optimus PRIME Active Member

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    I don't think we have to switch back to EV mode to regen charge the battery. It does that by default just from braking. If that's what you are referring to?
     
  13. bisco

    bisco cookie crumbler

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    force charge, which runs the engine to charge the battery, resulting in lower mpg's.
     
  14. fotomoto

    fotomoto Senior Member

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    No, the Energi like any hybrid does that too but...... in HV mode it will try to use that extra regen almost immediately to boost fuel economy by using the juice more than the ICE while also keeping the battery's SOC around the same (thus not banking it).

    When I switch to EV mode before the heavy braking it will (software wise) move the SOC baseline up (thus gain EV miles). I switch back to HV mode before the next throttle application so now the car will again operate as a hybrid but around the new, higher SOC and not eat into the banked savings. Does that make sense? :confused:
     
  15. inferno

    inferno Senior Member

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    I bank ev in my pip. When I run out of ev range I can sometimes get 1-2 miles back. On a long hill that I usually take in my rides I can get 4 miles of ev back.
     
  16. Andyprius1

    Andyprius1 Senior Member

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    I don’t want to get into specific models but I believe every Prius can go into a manual self charge mode. This was true on my 2005, 2012 and now my prime. I forget all the steps, but it involves putting the car in drive, keep left foot on brake pedal, step on accelerator pedal and keep it there. For added safety you may actuate the emergency brake. Of course on the Prime this mode is now built in and one does not need to park. As for driving and charging Bisco is correct, hills will do it.
     
  17. Mayank Jain

    Mayank Jain Member

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    I saw that in B mode, the moment you take foot off gas, regen braking kicks in and charging starts. If loosing speed is not a concern, is this a better idea to build SOC?

    Two instances that comebto my mind
    - when you see that you are going to run into a red light from a distance, put PiP into B mode and let is slow down with regen
    - as you said : going down from a long hill :)

    Your thoughts?

    Posted via the PriusChat mobile app.
     
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  18. jerrymildred

    jerrymildred Senior Member

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    I experimented with it and decided it was a pain in the pattooty and didn't get me any better range or mileage anyway. ;)

    You can regen easier as you approach a stop by simply using your right foot. And you have the added benefit of tailoring your deceleration rate to bring you smoothly to a stop at the right place. B Mode applies a fixed deceleration rate that may or may not match what you need, and you'll still need to use that right foot to get stopped anyway. B Mode is designed to slow you on a long, steep descent so you don't have to use the brakes so much and risk overheating them.

    I'd say go ahead and experiment with it and see if you agree. There's no real harm in it. This is such a fun and versatile car! (y)
     
  19. Prodigyplace

    Prodigyplace Senior Member

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    That may be the case with the PiP but I have heard of many people force charging in the Prime.

    I guess I need to summon @bwilson4web to settle this with data. :D
     
  20. bisco

    bisco cookie crumbler

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    i have never used b mode. pulse and glide works great around here, but we're flatlanders. i wouldn't want to be thinking about reaching for the shifter when approaching a red light at high speed. at low speed it won't help.
     
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